Having trouble to get the accurate size for the hole of products? Let us teach you step by step, if you need video for it, contact us to get it now! Prepared tool: Spirit level , Tape measure Step 1: Use a spirit level make sure the rough opening is align Step 2: Place the tape parallel to the hole bottom, measure the hole width in three sections (Remark: 3 sections including 1) The widest; 2) The middle 3) The shortest ) Step 3: Place a tape measure vertical to the hole bottom, measure the height in three sections (Remark: 3 sections including 1) The widest; 2) The middle 3) The shortest ) Step 4: Measure the height from the floor to the hole bottom in three sections Step 4: Measure the wall thickness around the hole , if possible, measure the 4 side (Also need in 3 sections) Above are the steps for getting more accurate size, if you still having trouble, welcome to contact us anytime.