That depends on how often you play and how sensitive you are to the tension loss in the strings. In general, if you play once a week restring once a year. If you play twice a week restring twice a year and so on.
Just because the string has broken doesn't mean it hasn't lost tension.
Do the caps come in different sizes?
The caps are all handcrafted one at a time. No two caps are cut the same. Some fabrics join together in different thicknesses that affects the fit and feel. I often say one size fits many. I list the cap's measurements. There is a piece of elastic in the back of each cap the gives about an inch(2.54cm).
For early birds and night owls alike
I often start by 6:00am. I will make accommodations for late evening drop offs or pick ups.
Willing to meet up for racquet exchange.
More than happy to meet you if I'm out on my bicycle.
Staff of one.
I'm a one man gang. I curate the fabrics, cut the patterns and assemble each cap.