The multivariate Dirac delta distribution can be - more or less intuitively - be expressed as
\begin{align} \delta(\mathbf x) = \begin{cases} \lim\limits_{a\rightarrow0} \quad \dfrac{1}{a^n} & \forall x_i \in [-\frac a2,\frac a2], 1\le i\le n \\[6pt] \quad 0 & \text{otherwise} \end{cases} \end{align}
where
$$ \int_{-\infty}^{\infty}\cdots\int_{-\infty}^{\infty} \delta(\mathbf x) \text{ d}\mathbf x = 1 $$
Is there an "opposite" of that, which can be expressed as
\begin{align} \epsilon(\mathbf x) = \begin{cases} \lim\limits_{a\rightarrow\infty} \quad \dfrac{1}{a^n} & \forall x_i \in [-\frac a2,\frac a2], 1\le i\le n \\[6pt] \quad 0 & \text{otherwise} \end{cases} \end{align}
where also
$$ \int_{-\infty}^{\infty}\cdots\int_{-\infty}^{\infty} \epsilon(\mathbf x) \text{ d}\mathbf x = 1 $$
?
Is there a name for this distribution and/or a symbol?
For context: I am planning to use them in convolutions and I am treating them as probability densities.
Both limits $$\lim_{a\to 0} a^{-n} 1_{x\in [-a/2,a/2]^n}, \qquad \lim_{a\to \infty} a^{-n} 1_{x\in [-a/2,a/2]^n}$$ are perfectly rigorous definitions of distributions, the first one converges in the sense of distributions to $\delta$ and the second one to $0$.