Alternative to VIX when Volatilities are Low?

Can I trade anything other than VIX to bet on higher Volatilities? Yes. What strategy? Calendars slightly out of the money on the put side.

Trade Example

SPY $212.28. Buy 1 July 210 Put and Sell 1 Jun 210 Put. Total Debit around $1.30 ( I just bought it live pretty easily at $1.29).

If the market is slightly down Monday and between 207 1/2 and 212 1/2 and Volatility increases 1 point, I can be up around 8%.

Basically I can possibly be out of this trade with near 10% returns if SPY goes down even 1 point or 10 SPX points, very attainable!

What If Market Goes Up?

For me to be down around 10% on this trade, SPY would need to approach $216, SPY has never been there so far. I would probably just close the trade at that point.

Or I could turn the Calendar into a Double calendar at around the 216 price level by adding a 218 Call calendar with the same expirations. That would double the capital though.