diff --git a/SZDeviceSpecificLayoutConstraint.h b/SZDeviceSpecificLayoutConstraint.h
new file mode 100644
index 0000000..70c9400
--- /dev/null
+++ b/SZDeviceSpecificLayoutConstraint.h
@@ -0,0 +1,35 @@
+//
+//  SZDeviceSpecificLayoutConstraint.h
+//  DevSpecLayoutConstraintDemo
+//
+//  Created by Сергей Галездинов on 31.07.15.
+//
+//
+
+#import <UIKit/UIKit.h>
+
+@interface SZDeviceSpecificLayoutConstraint : NSLayoutConstraint
+
+/**
+ Set this property to YES if you want any new constant assignment to reflect proportionally on a specific device 
+ @note
+ default value is NO
+ */
+@property (nonatomic) IBInspectable BOOL changeProportionally;
+
+/**
+ Set this value to YES if you need to keep the constraint value always as specified for a specific device
+ @note
+ default value is NO
+ */
+@property (nonatomic) IBInspectable BOOL ignoreChange;
+
+/**
+ Set each of this constants independently
+ */
+@property (nonatomic) IBInspectable CGFloat constant4s;
+@property (nonatomic) IBInspectable CGFloat constant5;
+@property (nonatomic) IBInspectable CGFloat constant6;
+@property (nonatomic) IBInspectable CGFloat constant6Plus;
+
+@end
diff --git a/SZDeviceSpecificLayoutConstraint.m b/SZDeviceSpecificLayoutConstraint.m
new file mode 100644
index 0000000..e541ed9
--- /dev/null
+++ b/SZDeviceSpecificLayoutConstraint.m
@@ -0,0 +1,148 @@
+//
+//  SZDeviceSpecificLayoutConstraint.m
+//  DevSpecLayoutConstraintDemo
+//
+//  Created by Сергей Галездинов on 31.07.15.
+//
+//
+
+#import "SZDeviceSpecificLayoutConstraint.h"
+
+typedef NS_ENUM(NSUInteger, SZDeviceType) {
+    szdtUnknown,
+    szdtIPhone4s,
+    szdtIPhone5,
+    szdtIPhone6,
+    szdtIPhone6P,
+    MAX_DEVICE
+};
+
+@implementation SZDeviceSpecificLayoutConstraint {
+    BOOL _valuesSet[MAX_DEVICE];
+}
+
+SZDeviceType currentDeviceType = szdtUnknown;
+__attribute__((constructor))
+static void initializer()
+{
+    //we don't need a precise device determination, since the screen size in points really matters
+    //so, detect a particular device from the screen height
+    CGSize bounds = [UIScreen mainScreen].bounds.size;
+    switch ((int)MAX(bounds.width, bounds.height)) {
+        case 480:
+            currentDeviceType = szdtIPhone4s;
+            break;
+        case 568:
+            currentDeviceType = szdtIPhone5;
+            break;
+        case 667:
+            currentDeviceType = szdtIPhone6;
+            break;
+        case 736:
+            currentDeviceType = szdtIPhone6P;
+            break;
+
+        default:
+            break;
+    }
+}
+
+@dynamic constant;
+
+-(CGFloat)constant {
+    return [self specificConstant];
+}
+
+-(void)setConstant:(CGFloat)constant {
+    //change specific constant proportionally to new value?
+    if (!self.ignoreChange && self.changeProportionally && _valuesSet[currentDeviceType]) {
+        switch (currentDeviceType) {
+            case szdtIPhone4s:
+                self.constant4s *= constant / [super constant];
+
+            case szdtIPhone5:
+                self.constant5 *= constant / [super constant];
+
+            case szdtIPhone6:
+                self.constant6 *= constant / [super constant];
+
+            case szdtIPhone6P:
+                self.constant6Plus *= constant / [super constant];
+                
+            default:
+                ;
+        }
+    } else {
+        //should new value be ignored?
+        if (!self.ignoreChange && _valuesSet[currentDeviceType]) {
+            switch (currentDeviceType) {
+                case szdtIPhone4s:
+                    self.constant4s = constant;
+
+                case szdtIPhone5:
+                    self.constant5 = constant;
+
+                case szdtIPhone6:
+                    self.constant6 = constant;
+
+                case szdtIPhone6P:
+                    self.constant6Plus = constant;
+                    
+                default:
+                    ;
+            }
+        }
+    }
+
+    [super setConstant:[self specificConstant]];
+}
+
+#pragma mark internal methods
+
+-(CGFloat)specificConstant {
+    if (!_valuesSet[currentDeviceType]) {
+        return [super constant];
+    }
+
+    switch (currentDeviceType) {
+        case szdtIPhone4s:
+            return self.constant4s;
+
+        case szdtIPhone5:
+            return self.constant5;
+
+        case szdtIPhone6:
+            return self.constant6;
+
+        case szdtIPhone6P:
+            return self.constant6Plus;
+
+        case szdtUnknown:
+            return [super constant];
+
+        default:
+            return [super constant];
+    }
+}
+
+-(void)setConstant4s:(CGFloat)constant4s {
+    _constant4s = constant4s;
+    _valuesSet[szdtIPhone4s] = YES;
+}
+
+-(void)setConstant5:(CGFloat)constant5 {
+    _constant5 = constant5;
+    _valuesSet[szdtIPhone5] = YES;
+}
+
+-(void)setConstant6:(CGFloat)constant6 {
+    _constant6 = constant6;
+    _valuesSet[szdtIPhone6] = YES;
+}
+
+-(void)setConstant6Plus:(CGFloat)constant6Plus {
+    _constant6Plus = constant6Plus;
+    _valuesSet[szdtIPhone6P] = YES;
+}
+
+@end